Instead Costa was cautioned and the Portuguese manager said in a news conference: "We all explain to him what we want in the Premier League, what we want in Chelsea, what people want in the Premier League, what they don't like.

"The kid presents himself here today with a fantastic attitude, a competitive attitude but clean and polite. He has a clear penalty and it is no penalty and a yellow card.

"The kid was obviously frustrated. I hope he doesn't get more unfair decisions. I thought [referee Michael] Oliver had a good game but the linesman [Stuart Burt] didn't support him well in that situation."

Cesc Fabregas impressed on his Chelsea debut by playing a part in all three goals and Mourinho believes the former Arsenal captain will benefit from be granted a regular role in his team.

The Chelsea manager added: "I know him so well that I know exactly what he brings to my team. In Barcelona he was playing all over: No.9, fake No.9, No.10, winger, in so many positions. I know and he knows better than me what is his position and he is giving exactly what we need which is that stability, that quick thinking in midfield.

"He makes the right decisions and he brings other people in the right direction. [Nemanja] Matic was different playing different from last year because he can play now in a different way so I am really happy with Fabregas.

"The feelings are that when the players are your first choice, it is very difficult to make a mistake [in the transfer market] and Fabregas was our first choice for that position.

"I think the team played very well but I agree with Cesc being the man of the match because him and Matic they control the game and they dictate the intensity of the game. They are both good brains in this team."

Mourinho urged Petr Cech to remain at Stamford Bridge and fight for his place after Thibaut Courtois was selected in goal ahead of the veteran.

He added: "I want to keep, the club wants to keep and hopefully he stays. I know Petr for 10 years. I know he will not relax. He will not sit in a chair and say 'I have no chance.' He will be exactly the opposite. I am expecting him Wednesday to go to the training ground and fight."

After enduring a tricky start to his Manchester United career, perhaps it is fair that Marcos Rojo celebrated so boisterously as he watched his first professional club Estudiantes beat fierce rivals Gimnasia